Examples of the industrial fabrics heretofore used include papermaking fabrics such as a papermaker's forming fabric and a papermaker's forming canvas, nonwoven material manufacturing fabrics, sludge dewatering fabrics, building material manufacturing belts, and conveyor belts.
These industrial fabrics are processed in an endless manner, and attached to machines such as a papermaker and a dehydrator for use.
As a method of processing the endless shape, there are a large number of known methods such as a method of joining both ends of an industrial fabric by seams, a method of engaging loops formed on both ends using the warp of the industrial fabric itself with each other and passing a pin therethrough, a method of engaging spiral loops formed on both ends of an industrial fabric with each other and passing a pin therethrough, and a method of engaging metal hooks called clipper lacing attached to both ends of an industrial fabric with each other and passing a pin therethrough. These methods are employed in accordance with purposes.
However, each of the conventional processing methods had some problems.
When various performances such as the same smoothness as that of an ordinary part are required for a joined part of an industrial fabric, the method of joining by seams is the most suitable way in which the joined part is woven with the ordinary part and equally formed in substantially the same texture.
However, the method of joining by seams has a large problem that much labor is required, and has a critically large defect depending on devices to use.
Specifically, in the method of engaging the loops with each other in the endless manner, the endless or ended shape can freely be formed by extracting or inserting the joining pin. In the method of joining by seams, however, once the endless shape is formed, the shape cannot be returned to the ended shape until it is cut. If the endless or ended shape can freely be formed, the fabric having the ended state is extended between rollers of the device, and the endless shape can be formed on the spot during attachment to the device to use, so that the attachment to the device is very easy. For example, the attachment comprises setting the old used industrial fabric attached to the device to be in the ended state, connecting one end of a new industrial fabric to be attached to one end of the old fabric, operating the device to move and extend the industrial fabric between the rollers of the device, removing the old industrial fabric when the fabric is once moved around and entirely extended, and attaching the new industrial fabric in the endless shape.
On the other hand, in the method of joining by seams in which the endless or ended shape cannot freely be formed, a so-called cantilever system has to be performed. The system comprises supporting the rollers of the device on one side, removing supports, and other obstacles from the other side and inserting and extending the industrial fabric in a width direction from one side of the device.
However, the cantilever system has disadvantages that the manufacture cost of the machine itself increases, the device is enlarged in size, and that a large installation space is necessary.
Moreover, for the use of a very heavy or long industrial fabric, since it is difficult to insert the fabric, the system is unsuitable. Therefore, in the actual circumstances, the above-described cantilever system is unemployed in most cases excluding the papermaker's forming fabric used in the forming section of the paper making machine in which surface smoothness is regarded as very significant.
Therefore, in most cases the method of forming the loop or the method by the metal hook is employed as the method of forming the endless shape, because the ended shape can be formed again.